Galatians 1:1 - Wesley's Explanatory Notes

Paul, an apostle — Here it was necessary for St. Paul to assert his authority; otherwise he is very modest in the use of this title. He seldom mentions it when he mentions others in the salutations with himself, as in the Epistles to the Philippians and Thessalonians; or when he writes about secular affairs, as in that to Philemon; nor yet in writing to the Hebrews because he was not properly their apostle. Not of men — Not commissioned from them, but from God the Father. Neither by man — Neither by any man as an instrument, but by Jesus Christ. Who raised him from the dead — Of which it was the peculiar business of an apostle to bear witness.